The present invention relates to a reflection phase shifter composed of a short-circuited, reduced height waveguide in which there is disposed at least one switchable semiconductor element accommodated in a housing and wherein at least one tuning pin extends into the reduced height waveguide.
Such a reflection phase shifter is disclosed in the periodical Mikrowellen Magazin [Microwave Magazine], volume 8, No. 6, 1982, pages 688-690. In that phase shifter, the semiconductor element accommodated in the housing is a PIN diode which is fixed in a reduced height waveguide. However, this waveguide also has a reduced width so that it acts as a reverse-wave blocking waveguide. A plurality of tuning pins extending into the reverse-wave blocking waveguide are required to set the phase shifter to a desired phase angle and to tune the phase angle over a broad frequency band.